If you're the kind of daredevil who totally took the Coke and Pop Rocks challenge, you will love this intense scalp treatment. The exfoliating scalp cleanser foams up like a mousse, and attacks the skin with a blast of cold, bubbling effervescence. You can hear it snapping and popping on your scalp like Rice Krispies in milk. The foam contains amino acids and salicylic acid to remove dead skin cells, sebum and all of the styling-product gunk that weighs down hair. Use it alone for a deep clean, or follow with the brand's Scalp Therapy to encourage hair growth. If you really want to have some fun with this product, massage it into your head before the foam is gone, and the product will pop like popcorn and sizzle to the touch.